Sewing machine



Nov. 14, 1944. B. 1-. LEVEQUE 2,362,545

SEWING MACHINE Filed Feb. 27', 1942 2 Sheets-Sheet 1 Nov. 14, 1944. a. T. LEVEQUE SEWING MACHINE 2 Sheets-Sheet 2 Filed Feb. 27, 1942 Patented Nov. 14, 1944 UNITED STATES PATENT OFFICE SEWING MACHINE Bernard T. Leyeque, Wenham, Mass, assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application February 27, 1942, Serial No. 432,637 13 Claims. (01. 112 -34) The present invention relates to a machine for sewing shoe sole or other heavy leather with a two thread chainstitch seam similar to that disclosed in present inventors copending application for patent Serial No. 371,263, filed December 23, 1940. t I

The objects of the invention are to improve the construction and mode of operation a in a sewing machine of the type'referred to in such a way that a two thread chainstitch seam may be inserted with greater uniformity and accuracy than heretofore in respect to the locations of the threads and in which the operation may better be controlled to insert seams having different characteristics, the natures of which are explained more fully in inventors application above referred to.

and other objects are attained in the present embodiment of the invention by the use of a work penetrating awl sharpened to cut a needle receiving incision passing entirely throughthe work, which incision is of the proper shape to give the best thread arrangement for the type or work operated upon. Thus, the hooks adjacent the point of the needle may be formed with the greatest possible thread carrying capacityior'a given size of needle and thenecessity 'for providing unusual strength in the needle The machine of the pending application is provided with a rotary shoe supporting horn into the tip of which a double hook needle enters during ea ch'stitch forming cycle of operations and which is provided with a needle threada ing whirl. In this machine, the work is fed by a feed point engaging the surface only of the work, the needle forming its own perforation after the work has been fed. When a two thread seam is being sewn, the point of theneedle is sharpened in a manner to cause the positions 01 the threads in each completed -stitohfto be controlled uniformlyin a particular relationship according to'the type of workbeing o'perated upon. With one form of point on the" needle'the threads of a seam are caused to lie side by side in contact with the work. With another form on the needle point, one thread is laid on top of another, at least partially obscuring the-same from view. The relationship of the threads-in the seam may be chan'gedin this machine "from one characteristic to theother by changing the shape of the needle at its work penetratingpoint. Due to the presence of the hooks-near the p'oint of the needle in such amachine, it is-difficultiito form the needle point with a shape which will best cause uniform arrangements of i threads without affecting the thread carrying capacity of the needle. Accordingly, a further object-of the present invention is to prov ide a sewingmachine in which a double-hook needle isemployed having a capacity'for carrying"threads through the work in excess of that inthe machine of the application with the same size of needle-andin which there is a greater ability than in the prior machine to cause the threads --ina' seam to be arranged in uniform relation to each-other during successive needle --reciprocations. These point to enable it to form its own perforation in the work is avoided.

The whirl in the machine of the application is of relatively small size,being restricted to the outside dimensions at the tip of the work enteringhorn and the operations of the other stitch forming devices areso timed as to favor the operation of the whirl. According to a further ieature'ofthe present invention, the threads are laid in-the -hooks*of the needle by a looper having a shank extending parallel to the needle and thread guiding perforations are formed in the looper shank spaced to hold the threads separate and to carry eachth'read about the needle accurately at the' pos'ition of the respective hook. Preferably, the looper is actuated to cause the threadsto be wrapped about its own shank, thus shortening the lengths of threads between the looper and the needle as the threaded needle begins its return movement through the work. By shortening the lengths of the threads between the looper and theneedle, the spacing .between'the threads is more positively retained as the threads are .carried into the needle hooks, so that when the needle retracts, there will be no irregular thread movementsor improper looping efiects. As a further refinement-in the construotion of the looper, according to this feature of the-invention, the end of the looper shank is so tapered that the threads wrapped around the shank are released in sequence, the strain .imparted to the {needle during the looping operation being relieved relatively gradually and the likelihood of improper location of the threads in the {hooks of the needle being substantially avoided. Asa result,t he}operations of-the stitch forming devices, other "than the needle threading devices and-needle; may be given a greater proportion of time in each sewing cycle than in the machine of the application and conse' uently, a better seam is rendered possible with ess attention to} adjustments and'w'a'r of 1 the -rnaoh ine in general.

"Theseveral features of the invention consist also in the devices, combinations and arrangements of parts hereinafter described and claimed which, together with the advantages to be obtained thereby, will be readily understood from the following description, taken in connection with the accompanying drawings, in which Fig. 1 is a view in side elevation of a sewing machine embodying the features of the present invention; Fig. 2 is a plan view'on an enlarged scale of the sewing tension devices of the machine of Fig. 1: Fig. 3 is a plan view on a further enlarged scale of a portion of a seam sewed on the machine in which the threads are arranged side by side in contact with the work; Fig. 4 is a similar View of a portion of a seam sewed on the machine of Fig. 1, with the threads arranged one above the other, the underneath thread being partially obscured from view; Fig. 5 is a detail front view of a portion of the machine illustrating the operation of the stitch forming devices during the penetration of the work by the awl; Fig. 6 is a detail view of the same portion of the machine illustrating the positions of the parts during the beginning of the needle looping operation; Fig. 7 is a detail view of the same parts,-illustrating the completion of the needle looping operations; Fig. 8 is a further detail view of the same parts with the threaded needle being retracted from the work; and Fig. 9 is an enlarged view illustrating the manner of looping the needle and the positions of the threads taken between the needle and the looper of the machine.

The machine illustrated in the drawings is constructed to sew a seam consisting of two parallel threads 2 and 4, indicated in Fig. 3, which, for certain types of work, particularly with heavy leather as in shoe sole sewing operations, is preferably so inserted that the threads, at least at one side of the work, will lie in side by side relationship along the surface of the work. The advantage of such seam is that thetwo threads project above the surface of the work 'to a less degree than would a single thread of the same strength and the pressure of the seam is more evenly distributed on the work than with a single thread. In certain other types of work, such as with harder material, where there is less danger in cutting the work, it may be desirable to insert a seam such as illustrated in Fig. 4. In this scam, two threads 6 and 8 are employed and laid one on top of the other, thus partially obscuring the under thread. As described in inventors prior application above identified, an important factor in controlling the location of the threads in a seam is in the shape of the perforation in the 4 work through which the threads of the seam pass. In the machine of the application, a double hook needle is provided having a work penetrating point sharpened to form a crosswise incision similar to that indicated at H) for the seam of Fig. 3, and an incision similar to that indicated at l2 in the work lengthwise of the seam when it is desired to insert a seam such as is illustrated in Fig. 4. Due to the presence of the hooks near to the point of the needle in the prior machine, it is diflicult to shape the needle point in a manner which will form an incision to best advantage of the desired shape.

In the machine of the present invention, the incisions for each stitch are formed by a reciprocating work penetrating awl indicated at M mounted in a socket at the lower end of an awl bar l6 having a set screw [8 for securing the awl in place. The penetrating point of the awl is formed with a wedge-shapeacting to cut an incision in the work, which is illustrated herein as being a shoe sole I9, extending in the desired direction either crosswise, parallel to or at any suitable intermediate angle with relation to the seam line according to the position of the awl at which the set screw I8 is tightened. The double hook needle of the machine is indicated at 20 and is substantially the same in the arrangement of its hooks spaced lengthwise at the same side of the needle as in the machine of the prior application. The shape of the needle point in the present machine, however, is in the usual form with a centrally located point 2|, instead of knife edges, extending across the diameter of the needle shank, as in the application machine. For convenience of illustration, the machine in which the features of the present invention have been embodied has been selected from the type disclosed in U. S. Letters Patent to Merrick, Nos. 490,854 to 490,857, inclusive, all dated January 31, 1893. This type of machine has generally the same method of handling thread and forming each stitch as the machine of the application, but the time allotments in each sewing cycle differ somewhat from those in the prior machine, particularly by reason of the form of looper employed and the manner of feeding the work in the patented machine.

The double hookneedle has both hooks formed at the same side of the needle shank, as in inventors prior machine, so that separate threads may be laid in the hooks at the same time by a single looper. However, in order to hold the threads in the proper spaced relationship corresponding to the spacings of the hooks along the needle, the present looper indicated at 22 is provided with a downwardly extending shank arranged in parallel relation to the needle and formed with thread guiding eyes 24 and 2G spaced apart along the shank by a distance greater than the space between the hooks of the needle. This-greater spacing is necessary because the threads extending between the work and the looper are drawn through a single perforation in the work so that they diverge from each other as they approach the looper, thus being spaced a shorter distance apart where contact is made with the needle during looping.

As in the machine of the patents referred to, the illustrated machine is provided with looper actuating mechanism indicated generally by the numeral 28 which causes the looper shank to move in a continuous elliptical path about the needlewithout rotating about its own axis. As a result of this mode of operation, during movements of the looper after the threads are carried against the needle, the threads begin to wrap themselves about the shank of the looper, as indicated more clearly in Fig. 9, thus shortening the lengths of threads between the looper and the needle by equal amounts. When the position of Fig. 9 is reached, the needle begins its retracting movement from the work and as the retracting movement continues, there is a tendency for the threads suddenly -to become unwound from the shank of the looper and slackened somewhat in the tension under which they are held. To avoid suddenly slackening of the tension with the use of the looper herein described and to avoid any opportunity for the threads to become displaced from their respective hooks in the needle as a result, the end of the looper shank is formed with a tapered surface 30 which causes first the thread in the lowermost guiding eye 26 to be unwrapped and to slide around the end surface of the'looper and then the thread in the uppermost looper eye 24 toslide around the end surface of the looper. In this-way, simultaneous lateral thread movement with respect to the looper is avoided and there is less likelihood of entanglement in the threads or displacement from the hooks of the needle.

In order to feed the work a stitch, length during each sewing cycle, the needle is actuated by mechanism more fully described in the Merrick patents specified above, to move towards and from a position of alignment with the awl, as indicated in Figs. 6, 7 and 8. When the fully fed position of the work in Fig. 8 is reached, the needle is located approximately in line with the looper and the threaded hooks of the needle are about to leave the work. As the needle reaches its lowermost position, it is back fed, drawing the loops of thread carried thereby tightly and setting the stitch. Due to the spacing of the needle hooks along the needle, the hook more remote from the needle point causes the loop of thread 4 to be drawn further away from the work than the loop of thethread 2, thus tending to increase the tension on the thread 4 while each K stitch is being set. To prevent a greater tension from being imparted to the thread 4 carried by the more remote needle hook than to the thread 2 in the hook nearer the work while a stitch is being set, separate tension devices 32 and 34 of the character illustrated in Fig. 2 are arranged to act on the threads 2 and 4, respectively, the tension device 34 being set to impart a lighter tension to the thread 4 than the tension device 32 to the thread 2. With the proper setting of the tensions 32 and 34, the threads'2 and 4 may be led in side by side relation along the upper surface of the work with the same degree of tension, in spite of the greater movement of the needle loop formed in the thread 4 while the stitch is being set. When the awl is secured within its socket, as illustrated in Fig. 3, to cut an incision Ill in the work crosswise to theseam line, and the proper setting made for the tensions 32 and 34,-extremely uniform results may be obtained in a reliable manner not heretofore considered possible. When the awl is secured in position with its cutting edge extending along the seam line, as indicated in Fig. 4, it forms the correspond-. ingly directed incision l2 which tends to produce a seam having one thread 6 laid on the top of the other 8. To accentuate this positioning of the threads and to improve the uniformity with which these results are obtained, the thread 8 is led through that eye in the looper which will cause the thread 8 to be laid in the hook of the needle most remote from the needle point. When the threaded needle retracts from the work with the thread 8 in this position, it will cause the thread 8 to be drawn more deeply and become somewhat embedded in the work while the thread 6, pressing against the thread 8, will increase the depth verse" passagelfl extends through the needle bar 38 nearthe lower end of the socket 3B. The socket thus enters into the passage 43 and the passage is of such size that when a second needle indicated by the dot-dashlines 42 of Fig. 8 is inserted, it will provide an accurate gage surface forthe lower end of the needle. If thesewing needle 20 isthen inserted in the sprocket 36 with its lower end in contact with the second needle 42, tighteningof a clamp screw 44 against the needle in the socket will secure it in the desired sewing position without experimental adjustments. After securing the needle '20 in place, the second needle 42 may be removed. In case the needle then accidentally encounters a rigid object during sewing, it will be pressed down to which the thread 8 is embedded. These results may be obtained when the tension devices 32 and 34 are adjusted to provide equal tensions in the threads and may be influenced still further by increasing the tension on the thread 8 until it is substantially greater than that on the thread 6. i

To locate the needle 20 accurately with relation to the looper 22 so that no difliculty in adjustments will occur while replacing the needle due to breakage, or for other reasons, the needle is received in asocket 36 at the upper end of a reciprocating needle carrying bar 38 and a transwardly in the needle bar past the passage 48 against the frictional resistance of the set screw 44 without such breakage as is likely to occur when the end of theneedle is backed rigidly at the end of the socket.

The work is supported and clamped in the same manner as in the Merrick patents referred "to, by work support 46 and a presser foot48 acting to release the work during feeding movements-and the needle is guided by a cast-off 50 of w substantially the same construction and mode of operation as in said patents. The castolf 50, however, in the present machine, is extended vertically sufficiently to cover both hooks of the needle 2!] when the needle is retracted from the work. The needle covering surface of the cast-01f, however, does not interfere with the operation of the machine in the usual way with a single hook needle instead of a double hook needle.

The nature and scope of the invention hav ing been indicated and a construction embodying theinvention having been specifically described, what is claimed is:

1. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle constructed and arranged to carry a plurality of loops of thread through the work in the same relation to each other during successive sewing cycles, and an awl sharpened to cut a needle receiving incision in the work with the cut directed to cause the threads when tensioned to be drawn into the same respective portions of the incision with uniformit throughout a seam. '2. A sewing machine for Operating upon sole leather or similar material having, in combination, stitch forming devices including a needle 7 having a shank provided with a plurality of thread receiving hooks for carrying separate loops of thread in the same relation to each other through the work during successive reciprocations of the needle, and an awl sharpened to cut a needle receiving incision in the work directed to cause the thread carried by each hook of the needle when tensioned to be drawn into the same respective portion of the incision with uniformity throughout a seam.

3. A sewing machine for operating upon sole leather or similar material having, in combinatlbn, stitch forming devices including "a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving. hooks spaced along the needle adjusted to apply a stronger tension on the thread having its 100p carried through the work last during each stroke of the threaded needle through the work 4. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving hooks for carrying a plurality of loops of thread with the bight of the loops spaced along the shank, and-individual tensions for the threads carried in the hooksadjusted to apply a weaker tension on the thread having its loop carried through the work first during each stroke of the threaded needle through the work.

5. A sewing machine 'for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carrying a plurality of loops of thread through thework, having a thread receiving shank cone structed and arranged to carry the loops in the same relation to each other during successive sewing cycles, and an awl sharpened to cut a needle receiving incision in the work with the i cut directed crosswise of the seam line to cause the threads, when tensioned, to lie side by side along the surface of the work.

6. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carrying a plurality of loops of thread through the work, having a thread receiving shank constructed and. arranged to carry the loops in the same relation to each other during successive .J sewing cycles, and an awl sharpened to cut a needle receiving incision in the work with the cut directed lengthwise of the seam line to cause the threads, when tensioned, to overlie one'another with the outer thread obscuring the thread beneath from view.

'7. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices includin a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving hooks spacedralong the shank, and a single looper for laying a plurality of threads in the hooks of the needle in the same relation to eachother during successive needle reciprocations comprising a shank extending along its end parallel to the needle and having thread guiding eyes spaced along the shank to hold individual threads extending therethrough separate and to carry simultaneously each thread about the nee-dle at the a hook.

8. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carying a plurality of loops of thread through the work having a shank provided wit-h a plurality of thread receiving hooks spaced along the shank, and a single looper for laying a plurality of loops of thread in the hooks of the needle in the same relation to each other during successive individual reciprocations comprisinga'shank' extending along its end parallel to the needle and having thread guiding eyes spaced along the shank to hold individual threads carried thereby separate from each other and to'carry the threads about the needle simultaneously at the positions of the hooks without rotating the shank itself, the threads being wrapped about the shank while being carried into the hooks of the neeposition of All dle to shorten the lengths of threads between the looper and needle-by equal amounts as the threaded needle begins its movement through the work.

9. A sewing machine for operating upon'sole leather orsimilar material having, in combination, stitch form devices including a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving hooks spaced along the shank, and a single looper for laying a plurality of loops of thread in the hooks of the needle in the same relation to each other during successive individual reciprocations comprising a shank extending along its end parallel to the needle having thread guiding eyes spaced along the shank to hold individual threads carried thereby separate from each other and to carry the threads dle begins its movement through the Work, and

a tapered surface at the end of the shank for causing the threads wrapped around the shank to slide between the end of the shank and needle in sequence as the needle is retracted from the work.

10. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving hooks spaced along the shank for carrying loops of separate threads through the work, means for cutting an incision for the threads in the work extending crosswise to the seam line, and tension devices acting on 11. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving hooks spaced along the shank for carrying loops of a plurality of threads through the Work, means for cutting an incision for the threads in the work extending along the seam line, and tension devices acting on the respective threads for imparting a substantially greater tension to the thread carried by the hook of the needle more remote from the needle point to cause the threads of the completed seam to overlie one another with less tension in the outer thread than in the'thread beneath.

12. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving hooksspacedlay individual threads extending in diverging relationship from the work to the-looper with'the:

same spacing as the needle hooks during loop- 13. A sewing machine for operating upon sole leather or similar material having, in combination, stitch forming devices including a needle for carrying a plurality of loops of thread through the work having a shank provided with a plurality of thread receiving hooks spaced along the shank for carrying loops of a plurality of threads through the work, a looper having a shank pro- 10 vided with thread guiding eyes along the shank spaced a greater distance apart than the space between the hooks of the needle to lay individual threads extending in diverging relationship from the work to the looper with the same spacing as the needle hooks during looping, and mechanism for actuating the looper in a continuous path about the needle without rotating the looper about the axis of its shank.

BERNARD T. LEVEQUE. 

